Gaseous electric discharge device



Jan- 14, 1964 A. w. cooLlDGE, .JR 3,113,073

CEsEoUs ELECTRIC DISCHARGE DEVICE Filed OCC. 2e, 1961 FlG.l.

fill

RNEY. S

CONTROL ^27 CIRCUIT HIS ATTO AINVENTOR. ARTHUR w. CCOLIDGEJR. BIA/@AkqAwww@ 4./

United States Patent O iiiil GSEUS ELECT" C BiSCHARGE DEVECE Artaur W.Cooiidge, Er., Scotia, NKY., assigner to Gener-ai Eiectric Company, a c:poration of New York Fiied st. 26, 196i, Ser. No. 1/-37,S49 2i? Claims.(Ci. 313-24) My invention relates to gaseous electric discharge devicesand pertains more particularly to devices of this type including new andimproved means for increasing the power-dissipating capacity, or powerhandling capabilities, thereof.

In the operation of some gaseous electric discharge devices, such, forexample, as high-power thyratrons, the anodes of the devices arerequired to withstand and dissipate substantial amounts of heat orpower. Generally, such devices are adapted for such operation throughthe provision of cooling means, which at the higher power levels, isusually a form of liquid cooling means. As power levels increase therate of coolant flow is generally required to increase, otherwiselocalized boiling tends to occur together with the formation of a vaporshroud about the anode surface to be cooled. These phenomena reduce theheat transfer to the coolant and subject the device to possible run-awayoperation or burn-out and destruction of the tube. Thus, it is desirableto provide means which will enable power level increases withoutincreasing substantially the coolant ow necesary to carry away the heatto be dissipated. Additionally, from the standpoint of economy inmaterials and coolant requirements it is generally desir-able to providemeans which will enable more efficient use of coolant flow. increasedthermal efciency enables construction of physically smaller coolingsystems and reduces the required rate of coolant flow to dissipateeffectively the heat resulting from operating a device at a given powerlevel.

Accordingly, a primary object of my invention is to provide a new yandimproved gaseous electric discharge device.

Another object of my invention is to provide a new and improved gaseouselectric discharge device including new and improved means forincreasing the power handling capabilities thereof.

Another object of my invention is to provide a new and improved gaseouselectric discharge device including new and improved cooling meansyadapted for substantially increasing thermal eiciency.

Another object of my invention is to provide new and improved gaseouselectric discharge device including a new and improved anode assemblyincluding means for reducing substantially the electron density at theelectron collecting surface thereof.

Another object of my invention is to provide a new and improved gaseouselectric discharge device including a new and improved anode assemblyincluding means for diffusing the plasma column approaching the electroncollecting surface therein and for affording increased collecting areafor the diffused column for any given device diameter.

Another object of my invention is to provide a new and improved gaseouselectric discharge device including a new and improved anode assemblyincluding means affording all of the desirable operational advantages ofhaving a planar anode element located in closely spaced relation to agrid in the device without the heat dissipating limitations inherent instructure wherein the same anode element serves also as yan electroncollector.

Still another object of my invention is to provide a new and improvedgaseous electric discharge device including new and improved means foreconomically obtaining increased thermal efficiency.

li Patentes aan. ia, ies/i ice Further objects and advantages of myinvention will become Iapparent as the following description proceedsand the features of novelty which characterize my invention will bepointed out with particularity in the claims rannexed to and formingpart of this specification.

In carrying out the objects of my invention, I provide a gaseouselectric discharge device comprising an envelope containing an anodeassembly and a cathode assembly in axially spaced relation, `aperturedcontrol and gradient grids interposed in axially spaced relation betweenthese assemblies and an ionizable lling. The anode assembly comprises animperforate conductive collector element which can advantageously becup-shaped and which constitutes a wall section `at one end of theenvelope, is `adapted for liquid cooling and is mounted in substantiallyspaced relation to the grids with the open end thereof facing the grids.The anode assembly also includes a perforate non-collecting or virtualanode element mounted in closely spaced parallel relation to thegradient grid. A tubular highly refractory insulator extends from thevirtual anode element into the open end of the cup-like collectingelement. The virtual anode element and collecting element can beconnected through either a high resistance resistor or through a lowintensity discharge or ionization internally 0f the `anode assembly. Theapertures in the grids and virtual yanode element are out of register ormisaligned to provide a tortuous electron path from the cathode to thecollecting element. Barrier means in the envelope between the wallsthereof and the refractory insulator minimize any tendency towardundesired arcing between portions of the virtual anode and collectinganode.

For a better understanding of my invention reference may be had to theaccompanying drawing in which:

FIGURE 1 constitutes a schematic and partially sectionalized elevationalview of apparatus constructed in accordance with an embodiment of myinvention;

FIGURE 2 is a sectional view taken along the line 2 2 in FIGURE 1 andlooking in the direction of the arrows; and

FIGURE 3 is an enlarged fragmentary schematic illustration of `a modiedform of my invention.

Referring to the drawing, there is shown in FIGURE 1 a high-voltagegaseous electric discharge device of stacked construction which forpurposes of illustration can cornprise a high-power hydrogen thyratronincluding -an envelope generally designated 1 and provided with ahydrogen filling. The disclosed device includes a cathode assembly 2, ahydrogen reservoir 3, a control or triggering grid 4, a gradient grid 5and an anode assembly generally designated 6. Herein the term gradientgrid is used to refer to `an Iapertured electrode positioned between thecontrol grid 4 and the anode assembly 6 and adapted for being operated`at an intermediate potential effective for assisting the control gridin holding oif an electric discharge between the cathode and anodeassembly and until a desired operational time.

The envelope 1 com-prises at the lower end thereof a conductive section`it? including a cylindrical metal wall section i1 and metal lower andupper header elements l12 and i3, respectively, having rims sealed in aVacuumtight manner to the ends of the cylindrical section 11. The lowerheader i2 is `apertured centr-ally at 14 and has sealed thereto incommunication with the envelope section it) through the aperture .14 areservoir housing l5 containing the reservoir 3` which is shown inoutline. The housing `15 comprises an upper met-al sealing ring 16brazed to the outer surface of the header 112, a cylindrical ceramicwall section 17 brazed in the ring 16, a lower sealing ring 18 brazed tothe outer end of the cylinder 17 and a metal header 19 which is sealedto the ring 18 and closes the lower end of the tube envelope. A pair ofleads 2t? connected to a heater included in the reservoir structure 3:but not shown, extend through the header i9 in suitable mutuallyinsulated relation and are connected externally of the tube envelope toan appropriate reservoir power supply 2l. In any suitable manner thepower supply 2l can be controlled selectively for selectively energizingthe reservoir heater thereby :to generate hydrogen for repleuishing thetube filling when, for example, the pressure thereof is reduced, as bycleanup or absorption of hydrogen by the materials of the device.

The cathode assembly 2 can comprise any suitable indirectly heatedstructure adapted for providing a copious supp-ly of electrons whenenergized. Additionally, the cathode assembly is suitably mounted in themetal section il? of the envelope in insulated relation thereto andincludes leads 22 provided ffor completing a circuit through Ithe heater(notshown) of the cathode assembly. The leads 22 extend through theheader 12 in suitable mutually insulated relation and carry llexibleconnectors 23 located externally of the tube envelope. The connectors 23are adapted for being electrically connected to the opposite sides ofany suitable `cathode heater power supply 24 which can be selectivelycontrolled for selectively controlling cathode energization. By meansnot shown, the cathode 2 is connected to the header 19 and, thus, thelatter is adapted for serving as a cathode contact..

Sealed across the central opening in the upper header member d3 is thepreviously referenced control grid 4 which, as seen in FIGURE l, isrelatively thick in construction. Also, as seen in FIGURE 2, grid 4includes a plurality of parallel elongated apertures or slots 2S. Thecontrol grid 4 is conductively joined to Ithe metal section of the tubeenvelope by a braze between the marginal area of the `grid and the upperheader 13. Thus, the metal section of the envelope operates at controlgrid potential. Brazed to the lower end of the cylinder l1 is aconductive ange `26 which is adapted both for mounting the device andfor serving as a grid contact, in which case it is electricallyconnected to one side of a control or triggering circuit generallydesignated 27. The circuit 27 -is adapted to provide preferably arectangularly-shaped ignition pulse or signal indicated by the curve3ft. Any one of a number of available circuits of prior art type issuitable for providing such -a signal in a predetermined timed relation.The effect of a signal 30 will be discussed in detail hereinafter inconjunction with the description of Ithe overall operation of thedevice.

Above the control grid 4 the envelope l comprises three coaxialgenerally cylindrical or annular insulators, or insulative wallsections, Syl-33. The insulators '3l-33 are preferably `formed of anysuitable insulative, highstrength and highly refractory ceramic materialadapted for being metallized in order to facilitate the provision ofceramic-to-rnetal bonds or brazos between the ends of these sections andmetal portions of the mentioned electrede assemblies. For example, thesections 31-3-3 can each Ibe formed of la `ceramic material knowngenerally in the art as alumina, which materials are adapted for beingprovided with metallized areas in a manner disclosed in U.S. Patent No.2,667,427, issued January 26, 1954, to Henry l. Nolte, `and assigned tothe same assignee as the present invention. When metallized, the ceramiccan be hermetically sealed to a metal member or another metallizedmember by means of any one or more of the various soldering or brazingtechniques well known in 'the art.

The upper section of the envelope which comprises the ceramic section 3lsupports the gradient grid 5 and the anode assembly generally designated6. More speclically, the lower end of the insulator 31 is metallized, asby substantially the same process referenced above, and is hermeticallybonded to the upper outer marginal area of the control grid 4.1. Theupper end of the cylinder 3l is similarly metallized and is brazed to aradially extending 'd flange 3-3- of a cup-shaped member 3S Ihaving gridgradient 5 as its 1bottom surface. Cup-shaped member 395 extendsreentrantly in the cylinder 3l with the walls thereof in close parallelspaced relation. The bottom of the member 35 which is gradient grid 5 isperforate and extends in closely spaced parallel relation to the controlgrid 4. The apertures in the grid 5 are also preferably Slot-like andparallel and are out of register with the slots in the control grid 4 toprovide rfor an indirect or tortucus electron path thereacross, or toavoid presentation to the Acathode of a direct straight-line electronpath toward the anode assembly. The gradient grid 5 is preferablyoperated at a potential ybetween those of the anode and control grid bymeans of a suitable connection to a voltage divider (not Shown)connected between the anode and control grid or between anode andcathode. n fact, any means adapted providing a sui-table intermediatepotential for the gradient grid can be employed.

Hermetically bonded to the upper side of the gradient grid flange 34 isthe lower metallized end of the ceramic cylinder 32. The upper end ofthe cylinder 32 is also rnetallized and has hermetically bonded theretoa radial flange *36 on a deep-drawn cup-like conductive member 4Q.Member tl comprises part or the above-referenced anode assembly 6 andshall hereinafter be referred to as the non-collecting anode or virtualanode inasmuch as it serves to present a perforate element surface 41 atanode potential immediately adjacent the gradient grid 5 but `does notserve to collect any appreciable amount of anode `current during aconductive discharge inthe device. The virtual anode '4o issubstantially elongated and extends reentrantly in both the ceramiccylinder 32 and the cup 35. The upper section of the virtual anode 40has a diameter which places its side walls in closely spaced parallelrelation to the ceramic cylinder 32 and the lower section .is somewhareduced in diameter, adapu'ng it for closely spaced parallel relation tothe inner side Wall of cup-shaped member 35 in which it extends. Theperfcrate element 4l of the virtual anode is planar and extends inclosely spaced parallel relation to gradient grid 5. Additionally,perforate element 41 of the virtual anode 4d includes an inner perforatelbaille 41. The apertures in element 4J., of the virtual anode di), andthe baffle `All are also in the yform of parallel slots and out ofregister with each other, `and the apertures in ethe perforate element4l are out of register with those in adjacent gradient grid 5. Thisserves Ifurther to render the electron path across the electrodeassemblies more tortuous .and indirect. Also, it has a desired dispersalor diffusive elfect on electrons passing through this region of thedevice.

Fitted tightly in the reduced end of the virtual anode 4t? is anelongated and highly-refractory insulative member d2. The member 42 istubular and preferably formed of quartz. Additionally, the tubularmember 42 extends from a point immediately adjacent the perforatedelement 41 of the virtual anode all to a point inwardly of the open endof an inverted cup-shaped imperforate element or collecting anode memberd3 which also comprises part of the anode-assembly 6. The collectinganode 43 is preferably formed of copper or any suitable high thermalcon-- ductivity meal and 4to have relatively thick wallsadapting it forsubstantial thermal conduction and for being impinged without damagelthereto by electrons. 4In the arrangement as illustrated in FIG. l,collector anode 43. is axially spaced from the perforated element 41 adistance substantially greater than the distance between the perforatedelement 4l and control electrode 4. The imperforate element or collectoranode 43 is located or positioned on that side of the perforated element41 which is remote from, or opposite from, the side which faces thecontrol electrode 4. Additionally, the collecting anode 43 is sealed atthe rim thereof to a metal sealing ring 44!- which has la ange 45 bondedat the rim thereof to the rim of an annular combined sealing member ,andshield` or barrier 45. A shielding function of this member will bedescribed hereinafter.

The sealing member 46 -is hermetically bonded to the metallized upperend of the ceramic cylinder 33. The lower end of the cylinder 33 is alsometallized and is hermetically bonded to a flange 47 on a shield ring orbarrier element 4, the shielding function of which will also bedescribed hereinafter. The flange 47 on the ring 48 and the flange 36 onthe virtual anode 4i? are hermetically sealed at the rims thereof forcompleting the envelope assembly.

The collecting anode 43 is fitted with a fluid-type cooling meansgenerally designated Si) and adapted for having a coolant such as watercirculated therethrough. As illustrated in FEGURE l, this structure cancomprise an outer jacket 51 connected in a leak-proof manner about thecollecting anode 43 and having a coolant outlet 52 at the upper end.Fitted over the collector 43 in the jacket 5l is a coolant path-definingmember or inner jacket 53 which is cup-shaped and has a helicaldepression or corrugation 54 formed therein, as by hydroforming orrolling, and engaging the outer surface of the collecting anode 43. Acoolant inlet 55 is fitted in the upper end of the member 53 and extendsin a sealed manner through the outer jacket l. Thus is provided acoolant flow path extending downwardly from the inlet 52 spirally andintimately about the outer surface of the collecting anode 43, into theouter jacket Si yand out of the outlet 52. Tinus, the collecting anode43 is adapted for providing a substantial surface area for interceptingelectrons resulting from a discharge in the device and presenting asubstantially large heat exchanging surface to the coolant flowingthrough the jacket.

During operation of the device the negative side of a utilizationcircuit generally designated 55 is connected to contact l' which isconnected internally of the envelope by means not shown to the cathode2. Also, the positive side of the circuit is connected to ian anodecontact 57 mounted `atop the coolant jacket 5l. The utilization circuit56 can be one of any number of well-known and readily available typessuch, for example, as a high-voltage, high-current power supply in theorder of 50 kv. and an appropriate load, and it need not be specificallyshown or described herein. With the cathode `assembly 2 energized and autilization circuit of the referenced -type applied to the device thereis a tendency for a `conductive discharge to occur between the cathodeand anode assembly. However, in normal operation this discharge is heldoft or controlled by the control grid 4 with the assistance of thegradient grid 5 and until the pulsing signal Sil is applied to thecontrol grid. Additionally, the virtual anode 40 and the collectinganode 43 are electrically separated by the insulator 33. However, priorto any operative conduction or electric discharge in the tube, thevirtual anode 4i? and collecting anode 43 lare at substantially the samepotential. This equipotential relationship can be provided by either (l)a high resistance resister connected between the collecting anode andvirtual anode or (2) the potential cqualizing effects of a long pathdischarge between the collecting and virtual anodes prior to conduction.

lf it is desired to use a high resistance connection between the virtualand collecting anode a simple circuit including a resistor 60 can beconnected between these elements external of the tube envelope, in themanner shown in FlGURE 3. In fact, any suitable high-resistanceconnection can be employed and, if desired, it can be located internallyof the envelope and mounted on the wall thereof.

if no direct resistance connection is made between the collecting andvirtual anodes in the manner shown, for example, in FlGURE 3, and if avoltage difference should exist between these elements a long pathdischarge through the quartz cylinder 42 will occur which will quicklyadjust the potential of the virtual anode to nearly that of thecollecting anode. Another way of viewing the phenomenon that causes thedirectly unconnected collecting and virtual anodes to be virtuallyequipotential is to consider that prior to operative conduction theseelements are connected through a low intensity discharge or ionizationwhich can be viewed as an operative equivalent of a high resistanceresistor.

Thus, prior to the initiation of a conduction discharge through thedevice, and with the collecting anode 43 connected to the positive sideof the high vol-tage utilization circuit in the manner illustrated, theperforated element 41 of virtual anode 4l) assumes essentially the samepotential as the collecting `anode 43 and -is in closely spaced parallelrelation to the gradient grids and, thus, the Kdevice is adapted for thesame high voltage operation as a device wherein an imperforatecollecting anode is provided in closely spaced relation -to the grid.When the control circuit is operated to apply the signal pulse 30 to thecontrol grid 4 to initiate a conduction discharge through the device,ionization of the gaseous filling in the device envelope results causingthe potential of the virtual anode 4h to fall to or assume essentiallycathode potential. In view of the fact that the virtual and collectinganodes are not directly conductively connected this assumption ofcathode potential by the virtual anode takes place vir-tuallyindependently of the collecting anode. When this occurs there results ahigh potential gradient between the virtual and collecting anodes `whichcauses anode current to be Vdrawn as a column or beam through theapertures in lthe perforated element 4l and baille 41' and to flowtoward the interior of the collecting anode. Due to the long path overwhich the electrons comprising the beam or column are caused to travelthrough the quartz cylinder 42, the electrons comprising the beam tendto diuse and impinge with a low electron density over both the internalbottom and side walls of the collecting anode. As a result, the power:dissipation density at the collecting anode surface is relativelysubstantially lower than if, vfor example, the virtual anode comprised`an imperforate planar element having the same diameter as the cupshapedanode and was adapted for collecting all the current. The collectingarea of the anode 43 is substantially greater than the projected area ofthe perforate element 4l. Expressed :in another manner, the impingingelectrons are more widely distributed over a substantial area ofcollector surface which minimizes any tendency toward acute heating ofany particular area thereof. Additionally, the use of both relativelyelongated side walls and the bottom Wall of the collecting anode aselectroncollecting surfaces Iresults in a substantially greater hea-texchange surface for presentation to the coolant ilowing spirally pastthe external surface of the collecting anode. lf the yanode comprised aplanar collector it would be limited as regards the amount of coolingmeans that could he employed effectively therewith for a given tubediameter. lIn my structure the cylindrical side walls and bottom of thecollecting ianode afford a substantially enlarged surface 4area exposedfor having coolant flow thereagainst. However, it is to be understoodfrom the foregoing that my invention is not limited to the use ofcupshaped anodes. For example, a planar anode can be employed in myinvention if an adequate cooling means can be provided therefor or ifthere is no limitation on the transverse dimensions of the tube.

In the presently-described structure the upper end of the quartzcylinder 42 extends slightly inwardly of the rim of the collecting anode43. Thus, when the virtual and collecting anodes are at widely differentpotentials during current conduction the quartz cylinder preventsundesired .arcing between the inner suriace of the collecting anode andthe inner `cylindrical surface of the virtual anode. Undesired arcing isalso prevented between Athe surfaces of the two anodes disposedoutwardly of the quartz cylinder 42 by means of provision :of the arcingshields or barriersformed as the inner extensions on the members 46VAand 47.

Thus, it will be seen from the foregoing that in my :structure .thevirtual anode is eriective primarily to provide a small area anodeclosely spaced relative to the gradient grid to adapt the device forhigh voltage operation prior to conduction. lt will also be seen fromthe forego-ing that the collecting anode provides a large area anode forcurrent collection during conduction. In view of the fact that thevirtual anode is by-passed during `current conduction and collects noappreciable amount of current, the virtual anode need not be providedwith cooling means and need not be constructed to withstandsubstantially high temperatures as does the collector anode.

While I have shown and described specilic embodiments of my invention ldo not desire my invention to be limited to the particular forms shownand descirbed and l intend by the appended claims to cover allmodifications within the spirit and scope of my invention.

What l claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A gaseous electric discharge device `comprising an envelopecontaining an ionizable filling, anode and cathode assemblies mountedyin insulated -axially spaced relation in said envelope, a controlelectrode mounted in said envelope in axially spaced-relation betweensaid anode and cathode assemblies, and said anode assembly comprising aperforate element in closely spaced relation to said :control electrodeand an impertorate element located on the side of said perforate elementremote from said control electrode, said imperforate element beingspaced a substantial distance from said perforate element relative tothe interelectrode spacing between said perforate element Iand saidcontrol electrode, and said imperfofrate element being adapted forcollecting charged particles passing through said perforate element. 'i

2. A gaseous electric `discharge device comprising an envelopecontaining an ionizable lilling, anode and cathode assemblies mounted ininsulated axially spaced relation in said envelope, a control electrodemounted 'in said envelope in axially spaced relation between said anodeand cathode assemblies, said anode assembly comprising a perforate`element in closely spaced relation -to said control electrode and animperforate element located on the side of said perforate anode elementremote from saidcontrol electrode and adapted for collecting chargedparticles passing through said perforate element, and said perforate andimperforate elements Ibeing spaced a substantial .distance from eachother and adapted for operating at substantially the same potentialbefore initiation of a conducting discharge.

3. A gaseous electric discharge `device comprising an envelopecontaining an ionizable filling, anode and cathode assemblies mounted ininsulated axially spaced relation to sa-id envelope, a control electrodemounted in said envelope in axially spaced relation between said anodeand cathode assemblies, said anode assembly comprising a perforateelement in closely spaced relation to said control element and animperforate element located on the side of said perforate element remotefrom said controll element and adapted or collecting charged particlespassing through said perforate element, said imperforate element -beingspaced from said perfor-ate element a distance substantially greaterthan the distance between ysaid perforate element-and said controlelectrode, and the collecting area of said imperforate element beingsubstantially greater than the projected area of said perforate element.

4. A gaseous electric discharge device comprising an envelope containingan ionizable filling, anode and :cathode assemblies mounted in insulatedaxially spaced relation in said envelope, a control electrode mounted:in said envelope `in axially spaced relation between said `anode andcathode assemblies, said anode assembly comprising a perforate elementin closely spaced relation to said control element and an `imperforateelement located on the side of said perora-te element remote from saidcontrol electrode and adapted for collecting particles passing throughsaid perforate element, said imperlorate element being spaced from saidperforate element a substantial distance relative to the spacing betweensaid perforate element and said control electrode, and a tubularhighlyrefractory insulative element internally disposed in said envelopeand extending `axially between said perforate and imperforate elements.

5. A gaseous electric discharge device comprising an envelope containingan iom'Zable iilling, anode and cathode assemblies mounted in insulatedaxially spaced relation in said envelope, a planar grid electrodemounted in said envelope in axially spaced relation between said anodeand cathode assemblies, said anode assembly comprising a perforateplanar element in closely spaced parallel relation to said gridelectrode and an imperfonate element located on the side of saidperforate element remote from said grid electrode and adapted forcollecting charged particles passing through said perforate element, andmeans effective for equalining the potent-ials of said erforate andimperforate elements prior to a conducting discharge through said deviceand for allowing said perforate element to assume cathode potentialindependently of said imperforate element during the initiation of aconducting discharge.

6. A gaseous electric discharge device according to claim 5, whereinsaid means for equalizing the potential of said perforate and imperorateelements comprises a high-resistance resistor connected therebetween.

7. A gaseous electric discharge device comprising an envelope containingan ionizable fitting, anode and cathode assemblies mounted in insulatedaxially spaced relation in said envelope, a grid electrode mounted insaid envelope in axially spaced relation between said anode and cathodeassemblies, said anode assembly comprising a perforate elements inclosely spaced relation to said grid electrode and adapted for servingas a non-collecting anode, and an mperforate cup-shaped element locatedon the side of said perforate element remote from said grid electrodeand having the open end facing said perforate element and therebyadapted for collecting electrons passing through said perforate element,said perforate and imperforatc elements being maintained in spacedrelation by insulating means, and means effective for equalizing thepotentials of said anode elements prior to a conductive dischargethrough said device and for allowing said perforate element to assumecathode potential independently of said imperforate element during theinitiation of a conducting discharge.

8. A gaseous electric discharge device comprising an envelope containingan ionizable filling, anode and cathode assemblies mounted in insulatedaxially spaced relation in said envelope, a grid electrode mounted insaid envelope in axially spaced relation between said anode and cathodeassemblies, and said anode assembly comprising a perforatenon-collecting element mounted in axially spaced relation to said gridelectrode, a cup-shaped collecting element constituting an end wallsection of said envelope, and insulating means maintaining saidnon-collecting and collecting elements in axially spaced relation.

9. A gaseous electric discharge device comprising an envelope containingan ionizable filling, anode and cathode assemblies mounted in insulatedaxially spaced relation in said envelope, a grid electrode mounted insaid envelope in axially spaced relation between said anode and cathodeassemblies, said anode assembly comprising a pertorate non-collectingelement mounted in close axially spaced relation to said grid electrode,a cup-shaped collecting element constituting an end wall section of saidenvelope and insulating means maintaining said non-collecting andcollecting element in axially spaced relation, and liuid cooling meansmounted in heat-exchange relation with the external surface of saidcollecting element.

1G. A gaseous electric discharge device comprising an envelopecontaining an ionizable filling, anode and cathode assemblies mounted ininsulated axially spaced relation in said envelope, a grid mounted insaid envelope in axially spaced relation between said anode and cathodeassemblies, and said anode assembly comprising a perforatenon-collecting element mounted in close axially-spaced rel tion to saidgrid electrode, a cup-shaped collecting element disposed axially remotefrom said non-collecting element and constituting an end wall section ofsaid envelope, an insulative wall section of said envelope maintainingsaid non-collecting and collecting elements in said Mially spacedrelation, and an elongated highlyrefractory tubular insulator extendingin said envelope from said non-collecting element partially into saidcollectng element.

ll. A gaseous electric discharge device comprising an envelopecontaining an ionizable iilling, anode and cathode assemblies mounted ininsulated axially spaced relation in said envelope, a grid electrodemounted in said envelope in said axially spaced relation between saidanode and cathode assemblies, said anode assembly comprising a perforatenon-collecting element mounted in close axially spaced relation to saidgrid electrode, a cup-shaped collecting element disposed axially andremote from said noncol ecting element and constituting an end wallsection of said envelope, an insulative wall section of said envelopemaintaining said non-collecting and collecting elements in said axiallyspaced relation, and an elongated highly refractory tubular insulatorextending in said envelope from said non-collecting element partiallyinto said collecting element, and a coolant jacket mounted on saidcollecting element and including means for circulating coolant over theexterior surface thereof.

12. A gaseous electric discharge device comprising an envelopecontaining an ionizable filling, anode and cathode assemblies mounted ininsulated axially spaced relation in said envelope, a control electrodemounted in said envelope in axially spaced relation between said anodeand cathode assemblies, an anode assembly comprising a hollow structureincluding a pair of oppositely extending cup-shaped conductive elementsseparated by an insulative section, one of said cup-shaped elementshaving a planar perforate bottom in closely spaced relation to saidcontrol electrode and the other of said cup-shaped elements beingimpertorate and constituting a current collector.

13. A gaseous electric discharge device according to l2, wherein saidimperforate cup-shaped element also constitutes a wall section of saidenvelope.

A gaseous electric discharge device according to claim 12, wherein bathemeans is mounted in said perorate conductive element and includesperforations which arc non-registering with respect to the perforationsin said perforate conducting element.

15. A gaseous electric discharge device comprising an envelopecontaining an ionizable filling, anode and cathode assemblies mounted ininsulated axially spaced relation in said envelope, a control electrodemounted in said envelope in axially spaced relation between said anodeand cathode assemblies, said anode assembly comprising a hollowstructure including a pair of oppositely extending cup-shaped conductiveelements separated by insulative section, one of said cup-shapedelements having a periorate planar bottom in closely spaced relation tosaid control electrode and the other of said cupshaped elements beingimperforate and constituting a current collector, and a highlyrefractory insulative tubular member extending in said hollow structurefrom a point adjacent said planar perforate bottom to a point locatedinwardly of the rim of said current collector.

16. A gaseous electric discharge device comprising an envelope includinga stacked array of alternate tubular insulative and conductive sections,axially spaced cathode and anode assemblies mounted in opposed ends ofsaid envelope, a perforate planar cont-rol element mounted transverselyin said envelope and axially spaced relation between said cathode andanode assemblies, said anode assembly comprising a hollow structureincluding a pair of oppositely extending cup-shaped conductive elements,one of said cup-shaped elements having a llange sealed between opposedends of a pair of said insulative wall sections and extendingrcentrantly in one of said insulative wall sections, said one elementalso including a perforate planar bottom in closely spaced parallelrelation to said control electrode and adapted for serving as a virtualanode, the other of said cup-shaped elements constituting a wall sectionof said envelope and joined at the rim thereof to an insulative wallsection of said envelope and adapted `for serving as a collecting anode,said last mentioned insulative wall section electrically separating saidwo cup-shaped elements, and means providing an indirect path of currentflow between said cathode and collecting anode during a conductiondischarge in said device.

17. A gaseous electric discharge device comprising an envelope includinga stacked array of alternate tubular insulative and conductive wallsections, axially spaced cathode and anode assemblies mounted inopposite ends of said envelope, a perforate planar control elementmounted transversely in said envelope in axially spaced relation betweensaid cathode and anode assemblies, a cup-shaped gradient grid electrodehaving a ilange sealed between opposed ends or a pair of said insulativewall sections and extending reentrantly in one of said insurative wallsections, said gra icnt gri-d electrode including a perforate planarbottom in closely spaced parallel relation t-o said control electrode,said anode assembly comprising a hollow structure including a pair ofoppositely extending cup-shaped conductive elements, one of saidlast-mentioned elements having a flange sealed between opposed ends of apair of said insulative wall sections and extending reentrantly in oneof said wall sections and nesting in said gradient grid, said oneelement also including a perforate planar bottom in closely spacedparallel relation to said gradient grid element and adapted for servingas a virtual anode, another of said cup-shaped elements constituting awall section of said envelope and joined at the rim thereof to aninsulative wall section of said envelope and adapted `for serving as acollecting anode, said first-mentioned insulative wall sectionelectrically separating said two cup-shaped elements, and the aperturesin said control electrode gradient grid and virtual anode being out ofregister to provide an indirect path of current llow between saidcathode and collecting anode during a conducting discharge in saiddevice.

18. A gaseous electric discharge device comprising an envelope includinga stacked array of alternate tubular insulativc and conductive wallsections, axially spaced cathode and anode assemblies mounted in opposedends of said envelope, a perforate planar control electrode mountedtransversely in said envelope in axially spaced relation between saidcathode and anode assemblies, said anode assembly comprising a hollowstructure including a pair of oppositely extending cup-shaped conductiveelements, one of said cup-shaped elements having a flange sealed betweenopposed ends of a pair of said insulativc wall sections and extendingreentrantly in one of said insulative wall sections, said one elementalso including a perlforate planar bottom in closely spaced parallelrelation to said control electrode and adapted for serving as a virtualanode, the other of said cup-shaped elements constituting a wall sectionof said envelope and joined at the rim thereof to an insulative wallsection of said envelope adapted for serving as a collecting anode, saidlastrnentioned insulative wall section electrically separating said twocup-shaped elements, and a highly refractory tubular insulator extendingin said anode assembly from said planar bottom of said virtual anode toa point inwardly of the rim of said collecting anode.

19. A gaseous electric discharge device comprising an envelope includinga stacked array of alternate tubular insuletive and conductive wallsections, axially spaced cathode and anode assemblies mounted inopposite ends of said envelope, a perferate planer control elementmounted transversely in said `envelope in axially spaced elation betweensaid Cathode and anode assemblies, said anode essernbly comprising ahollow structure including a pair of oppositely extending cup-shapedconductive elements, one of seid cup-shaped elements having a liengesealed between opposed ends of a .pair of said insulative wall sectionsand extending reentrantly in one of said insulative wall sections, saidone element also including a perforate planar bottoni in closely spacedparallel relation to seid control electrode and adapted for serving as evirtual anode, the other cup-shaped element constituting e wall sectionof said envelope and joined at the rim thereof to an insuletive wailsection of seid envelope and adapted for serving as a collecting anode,said lastrnentioned insulative Well section electrically separating saidtwo cup-shaped elements, and a highly refractory tubular insulatorextending in said anode assembly from said planar bottoni or" saidvirtual anode to a point in- I`Hardly of the rim of said collectinganode, and means interposed between said highly refractory insulator andthe wall of said envelope and axially disposed between the adiacent endsof said Virtual and collecting anodes providing a barrier to arcingtherebetween.

20. A gaseous electric discharge device comprising an envelope includinga stacked array of a .crwte tubular insulative and conductive wallsections, axially snaced Cathode and anode assemblies mounted in opposed'ids of said envelope, a perforate planar control cierne it mountedtransversely in seid envelope in axially spaced relation between saidcathode and anode assemblies, said anode assembly comprising a hollowstructure including a pair of oppositely extending cup-shaped conductiveelements, one of seid cup-shaped elements 11a a sealed between opposedends of a pair of seid insnlative Well sections and extendingreentrantly in one of said insulative wall sections, said one elementalso including a perforate planar bottom in closely spaced parallelelation to said control electrode and ef-ect fe for serving a virtualanode, the other of said cupwsliaped eleA s constituting a wall sectionof said envelope and joined et the rim thereof to en insulstive wellsection of said envelope and adapted :for serving as a collecting anode,seid lest-mentioned insnlative wall section elec cally separating saidtwo cup-shaped elements, and cool 1g means for said collecting anodeincluding 'means for circulating a coolant in heat-transferring relationwith the exterior surface thereof,

References Cited in the iile of this patent UNTED STATES PATENTS2,797,348 Natrous 25, i957

11. A GASEOUS ELECTRIC DISCHARGE DEVICE COMPRISING AN ENVELOPECONTAINING AN IONIZABLE FILLING, ANODE AND CATHODE ASSEMBLIES MOUNTED ININSULATED AXIALLY SPACED RELATION IN SAID ENVELOPE, A GRID ELECTRODEMOUNTED IN SAID ENVELOPE IN SAID AXIALLY SPACED RELATION BETWEEN SAIDANODE AND CATHODE ASSEMBLIES, SAID ANODE ASSEMBLY COMPRISING A PERFORATENON-COLLECTING ELEMENT MOUNTED IN CLOSE AXIALLY SPACED RELATION TO SAIDGRID ELECTRODE, A CUP-SHAPED COLLECTING ELEMENT DISPOSED AXIALLY ANDREMOTE FROM SAID NONCOLLECTING ELEMENT AND CONSTITUTING AN END WALLSECTION OF SAID ENVELOPE, AN INSULATIVE WALL SECTION OF SAID ENVELOPEMAINTAINING SAID NON-COLLECTING AND COLLECTING ELEMENTS IN SAID AXIALLYSPACED RELATION, AND AN ELONGATED HIGHLY REFRACTORY TUBULAR INSULATOREXTENDING IN SAID ENVELOPE FROM SAID NON-COLLECTING ELEMENT PARTIALLYINTO SAID COLLECTING ELEMENT, AND A COOLANT JACKET MOUNTED ON SAIDCOLLECTING ELEMENT AND INCLUDING MEANS FOR CIRCULATING COOLANT OVER THEEXTERIOR SURFACE THEREOF.